On assembling wind turbines, the rotor blades have to be attached at a large lifting height. Mobile cranes or crawler cranes are preferably used for this purpose. The rotor blade to be mounted has a large rotor surface and consequently a large exposed surface for the wind. To mount the rotor blade at the corresponding wind turbine, a sufficiently precise adjustment and stabilization of the taken-up rotor blade at the mounting height is required.
It is already known from the prior art for this purpose to take up the rotor blade by means of a blade. The latter is suspended at the load hook of the hoist rope and takes up the rotor component to be mounted in the corresponding mount.
It is, for example, proposed in DE 2006 015 189 U1 to fasten rotor blades via two control ropes at the two guy ropes of the Y-guying system of the main boom and to secure them against rotation. A disadvantage of the proposed solution is that the guy ropes run far away from the longitudinal axis of the main boom. The forces in the horizontally extending control ropes consequently substantially influence the guying forces of the Y-guying system and reduce the payload of the crane.
Constructions are furthermore known in which one or more additional ropes, also called guide ropes, is/are tensioned by means of at least one additional winch starting from the boom foot to the boom head. The mount for the rotor blade is connected via two control ropes to the tensioned rope or ropes.
The decisive disadvantage of these solutions now comprises the fact that additional winches and rope arrangements are absolutely necessary. The additional equipment articles mean, however, a disadvantageous weight increase of the crane and simultaneously an increasing production cost effort and servicing effort. Furthermore, it is necessary in solutions using two additional ropes to tension both ropes independently of one another. The tensioning force introduced per rope loads the boom since the resulting pressure load acts as an additional load on the boom. The attachment of two independent ropes likewise induces an additional lateral load on the boom if one rope is loaded more.